Membrane roofs utilize a membrane formed from polymers such as ethylene propylene diene monomer rubber (EPDM), thermoplastic olefin (TPO) or polyvinyl chloride (PVC) as a waterproof barrier. The membrane must be held on the roof in some way. There are a variety of different methods to do this including ballast (i.e., gravel), mechanical fasteners, and adhesives. The present invention relates to such membrane roofs fastened with adhesives.
There are a variety of different systems that have been employed utilizing different adhesives. One such system is disclosed in Venable U.S. Pat. No. 4,996,812. This patent discloses a foam polyurethane adhesive used to adhere a membrane to a roof structure. The membrane is a laminate having a fleece side and a polymeric membrane side. The fleece material improves adhesion between the membrane and the roof structure.
Another system is disclosed in Ritlin U.S. Pat. No. 6,742,313 which utilizes a very similar foam adhesive that is polyurea based. Other types of adhesives are used in addition to polyurethane adhesives and polyurea adhesives, such as thermoplastic adhesives and many different types of thermosetting adhesives.
The polyurethane and polyurea adhesives generally preferred are those with low elongation and high modulus. These adhesives are intended to provide high uplift resistance.